Abstract

Hexagonal InN layers were grown by molecular beam epitaxy and studied by high resolution electron microscopy and by photoluminescence spectroscopy. Inclusions of a few nanometers in diameter were found, which are among the smallest reported. Image simulation, beam sensitivity, and photoluminescence of the samples corroborate that these inclusions are indeed metallic indium. This letter provides evidence that nanoscopic metallic indiuminclusions can be present in InN crystals and have a strong influence on its optical properties.

Received 31 July 2007Accepted 14 August 2007Published online 06 September 2007

Acknowledgments:

One of the authors (T.P.B.) thanks the German National Academic Foundation for support. NCEM support under DOE Contract No. DE-AC02-05CH11231, AFOSR support under Contract No. FA9550-04-1-0408, and RFBR grants are acknowledged.